Subliming apparatus



Sept. 11, 1928. 1,683,931

I H. G. STONE SUBLIMING APPARATUS Filed June 2, 1922 2 Sheets-Sheet 1 ept. 11, 1928.-

.H. G. STONE SUBLIMING APPARATUS I v I Filed June 2, 1922 2 Sheets-Shut 2 @YMWT v I Patented Sept. 11-, 19 28.

UNITED STATES.

1,683,931 PATENT OFFICE.

HERBERT G. STONE, OF BRISTOL, TENNESSEE. v

SUBLIMING APPARATUS.

' Application filed June 2,

This invention relates to subliming apparatus; and it comprises a relatively long heated plane surface, regulable means for imparting heat thereto, conveyor means for passing pulverulent material thereover from end to end, a vapor chamber enclosing said surface, a series of transverse depending baf fies in said chamber and a subliming chamber laterally communicating with said vapor chamber and extending below the level of said heated plane surface, adapted for the reception and removal of sublimate; all as more fully hereinafter set forth and as claimed.

The present invention relates to an apparastance to be sublimed alters or decomposes.

3 It is therefore desirable in sublimation to be able to supply a relatively large amount of heat within a limited temperature range. The temperature must of course be above the subliming point but it must also be below any point dangerous to the substance to be sublimed or to materials associated therewith.

In the present invention, the material is treated as a relatively thin traveling layer or film passing along a plate with its upper surface kept at the subliming temperature or a few degrees above; the length (or time) of travel being sufl'icient to enable thedelivery of the necessary number of thermal units at this temperature to the material; under treatment. The vapors evolved are allowed to pass into a lateral chamber for condensation. Commonly, I make this chamber of rather large cross-section and, as these vapors are usually rather heavy and tend to fall rather than rise I give it a downward extension into which vapors can flow, considerably below the level of the hot plate. Advantageously, it also extends above this level for some dis.-

' tance. I provide a hopper or the like-at the controllable.

1922. Serial No. 565,448.

cool the inflowing' vapors to produce condensation thereof. Radiation from the chamber walls is usually suflicient to dispose of the heat taken up by the gaseous contents; although positive wall cooling means may, in some cases, be provided. A simple method of affording the additional cooling, .in many cases, is to spray the walls with water. Some-' times it is necessary to provide more orless heat within the chamber to prevent premature condensation; this being particularly the case with vapors forming only at rather high temperatures. This may be done by the introduction of steam, which may be superheated. Such an introduction of steam also oifers a means for diluting the vapors somewhat and thereby making the operation more Sometimes, however, in dealing with high temperature'vapors a little heat insulation on the subliming chamber is all that is necessary.

In the accompanymg illustration I have shown more or less diagrammatically, one embodiment of the described invention. In this showing Fig. 1 is a longitudinal vertical section through the sublimation chamber along line 11 of Fig. 2 with certain accessory parts and parts of the condensation chamber shown .in elevation, and

Fig. 2 is'a transverse section through the subliming chamber and condensation chamher along line 22 of Fig. 1.

Referring first to Fig. 1, element 1, as shown, is a. relatively long smooth surfaced plate of any convenient material, such as cast iron or steel. It is shown as heated by a bank of burners 2. Any convenient regulable means of heat-ing, however, may be employed, such as electrical heating, circulating.

ot oil, furnace gases, etc. Material moves along this plate. As shown, it moves from left to right. At the entrance is an unheated extension 3 of the plate upon which material can be deposited by any suitable feeding means, here shown as hopper 4:. Any convenient mechanical feeding means adapted to deposit material on 3 as a relatively uniform.

layer, usually rather thin, may be used.

-Passing over the surface of the plate is a con- 'veyor, here shown as a drag means 5, passing,

over wheels 6 and 7 and returning through the base of the apparatus. The drag elements can be of any desired type. As shownit carries transverse blade. members 8. If these be of, a plow-like form the speed of the '55 forward over the plate the drag constaiitly conveyor may be considerably greater than that of the material passing through the apparatus; and in this event, the conveyor has the additional function of disturbing the traveling layer of material and constantly exposing fresh surfaces for release of vapors. Enclosing the heated plate is vapor subliming chamber 9. As shown, it is provided with heat insulating means 10 and with swinging gates 11 and 12 at the two ends, these gates riding upon the conveying means and serving to prevent drafts. Usually, the operation is so controlled as to maintain about the normal atmospheric pressure within both chambers, giving no tendency either foran indraft or an outdraft: Within the vapor chamber, as shown, are provided a plurality of depending baffles 13 breaking it up into a pluralityof sub-chambers and decreasing any tendency towards longitudinal gas and'vapor movements. Referring now-to Fig. 2, the vapor chamber, as shown, has connected with it condensation chamber 14. As shown this is made of metal plates. A low longitudin a1 lateral bridge-wall or damv 15 along the side of the subliming chamber prevents solid matter carried forward by the drag from enter-- ing the condensation chamber. Vapors aris ing from the hot material overflow this lateral dam member and sink downward in the lateral condensation chamber. As shown, spray cooling means 16 may be provided for assisting in the cooling of the gaseous contents of this chamber. Inlet means 17 may be provided for admitting steam or other gas or vapor into the condensation chamber.

' Atthe bottom of the condensation chamber isshown conveyor means 18 for removing condensed solids.

Presuming the apparatus so far shown is to be used for recovering anthraquinone from I associated tarry matter and impurities in crude anthraquinone, the material to be treated is delivered on the unheated extension 3 of the hot plate and is carried forward within the chamber by the forward movement of the convedyor drags 8. Anthraquinone boils at 382 .and sublimes at temper- Presuming that it is to be sublimed at, say, 350C, and that because of the presence of impurities or for ot er reasons the material cannot be safely heated above, say, 370 (3., the hot plate may be heated to a temperature of 350? to 360 C. As the crude anthraquinone moves plate. The vapors which are'very heavy do not tendtojrise "far within, the subliming v chamber which, itLmay be noted, is desirable to have, as shown, rather low. These, vapors tend, on the other hand, to flow laterally across bridge wall 15 into condensation chammea er thraquinone which falls to the bottom. of

fchamber 14.. The hot gases separated from- "the solid sublimate rise in the chamber and are cooled by itsnvalls. There is to a greater or less extent, a gas circulation within the vapor chamber as indicated by the arrow 19. The crude anthraquinone is given a sufiicient time of exposure tothe heat in the vapor chamber to insure that the material delivered at the right hand end is substantially free of volatilizable matters. The spent material falls through opening 20 in plate 1 into waste receiving means 21. The operation of the device is exactly the. same, save for the temperatures to be maintained, in,subliming camphor, naphthalene, 'anthracene, etc. The apparatus may also beused for inorganic sublimable'material, such as corrosive sublimate, sal ammoniac, etc.

The vapor chamber and condensation chamber may be filled with suitable inert vaporsor gases, nitrogen, steam, products of combustion, etc. where this is desirable. As a rule, however, the materials treated evolve enough moisture, gases, etc. to furnish their own inert atmosphere;

. What I claim is 1. In asubliming apparatus, a plate-like heating member having a low lateral dam thereon, conveying and distributing means passing longitudinall thereover, rcgulable heating means there 'or, a vapor chamber above the heating member and a condensation chamber in free lateral communication withthe vapor chamber above the dam.

2. Subliming apparatus comprising a vapor chamber, means for heating a horizontal surface therein, a lateral dam on said sun heatedsurface and acondensing chamber in free lateralcommunication wlth thewapor chamber, said condensing chamber being of Substantiall greater capacity thanthe said 1 vapor cham er. 4

3. Subliming apparatus comprising a long .narrowyapor chamber, means for heating a horizontal surface therein, a lateral dam on said surface, means for moving and distributing the material to be heated longitudinally over said heated surface, and.a condensing chamber in free lateral communication with the vapor chamber, said condensing chamber being substantially co-extensive with saidvapor chamber and in communication therewith throughout .its length but of relatively greater capacity. l. Subliming apparatus comprising a vapor chamber, means for heating a horizontal surface therein, a lateral dam on-said surface, 4

means for movinganddistributing the ma- .terial to be heated-longitudinally over said heated surface, and a. condensing chamber in free lateral communication with the vapor substantially greater capacity than the said vapor,chamber and provided with exterior coolmgmeans.

5. Sublimmg apparatus comprising a vapoi: chamber, means for heating a horizontal surface therein, a lateral dam on said surface,

means for moving and distributing the material to be heated longitudinally over said heat ed surface, and a condensing chamber in free lateral communication with the vapor chamber, said condensing chamber being of substantially greater capacity than the said vapor chamber and provided with means for admitting fluid interiorly thereof.

6'. Subliming apparatus comprising a plate-like heating member, conveying and distributing means passing thereover, heatmg means therefor, a vapor chamber above the heating member, said vapor chamber be ing relatively long and narrow, and a con-- densing chamber in lateral communication with the vapor chamber throughout its length.

7. Subliming apparatus comprising a vapor chamber, means for heating material.

therein, means for conveying material to be heated therethrough, a. condensing chamber in communication therewith, and .baffles in the vapor chamber preventing substantial passage of sublimed vapors longitudinally therein.

8. Subliming apparatus comprising a plate-like heating member, conveying means passing thereover, heating means therefor, a vapor chamber above the heating member, a condensation chamber in lateral communication with the vaporchamber and extending above and below said vapor chamber, and means in the condensation chamber for the conveying and removing of condensed solids.

In testimony whereof, I have hereunto affixed my signature. HERBERT G. STONE. 

